Due to the advantages such as small volume, low power consumption and low manufacture cost, Thin Film Transistors (TFTs) have been widely applied to flat-panel display devices.
For a TFT display technology, on and off states of the TFT are controlled through gate lines. A signal is applied from a data line to a pixel electrode through the TFT, so as to form a driving electric field, thereby to drive a display function layer to display an image. For some display devices, e.g., electronic papers, the gate lines and the data lines are arranged very close to electronic ink, so normal display of the electronic papers may be adversely affected. A planarization layer is very thick, and it may be arranged on the gate lines and the data lines, so as to increase a distance between the electronic ink and the gate/data lines, thereby to reduce the interference of the signal from the gate lines or data lines on the electronic ink. However, due to the additional planarization, the manufacture cost may inevitably increase.